low/middle pairs can be devastating if someone doesn't raise their AQ/AK and flop comes AK5 and you have 55..... one of the biggest money makers is a flop like that in NL.

But also, as you get higher in NL stakes, you'll see drawing hands are very tricky to play, considering someone might make you pay 2x the pot to see the next card.

also, value betting is more for limit than NL, no reason to do pot sized bets with AK when you are clearly behind or even out of the hand.